The estrogens to which the invention pertains are called "free" estrogens, and they are known to have hormone effects on certain body functions. Estrogens include a group of steroid hormones essential for normal development and for the healthy functioning of the female reproductive system. Only a small percentage of estrogen (1% of total estrogens in human females) are not chemically bound; unbound estrogens are known as free estrogens. Evaluation of "free" estrogen levels can have diagnostic importance, as observed in the growths of certain estrogen dependent tumors, occurrence of cystic ovaries, and the regulation of possible endometriosis. In some female mammals, changes in concentration of free estrogens are known to occur at the time of embryo implantation, and before the onset of parturition. It is also known that free estrogen levels vary at different times in the life span of a mammal, During fetal development, the concentration of free estrogens is known to increase in the third trimester of pregnancy, due to increased levels of one estrogen form called estriol which is produced by the adrenal glands of the fetus. Prior to delivery, free estrogen levels increase significantly in serum and saliva of different species of pregnant mammals. After delivery, free estrogen levels fall rapidly in the mother, and babies have low levels of free estrogens.
It is also known that estrogen levels increase significantly in girls before they reach puberty. As women age, their ability to produce estrogen decreases after the onset of menopause, and free estrogen levels reach very low levels between 70 and 80 years of age. Free estrogen levels also fall when ovaries are removed from all animal species. Certain activities, such as excessive sports, can also diminish free estrogen levels. Some cases of anovulation have chronic high levels of estrogen, but fail to reach peak levels of estrogen concentration and can result in a condition known as cystic ovaries.
The body regulates the total amount of free estrogen at any given time. An ovulating woman can absorb at least 9 picograms of free estrogen in her saliva. A woman who is about to deliver a baby is able to absorb at least 200 picograms of free estrogens in her saliva. An older menopausal woman will be able to absorb 1-2 picograms of free estrogens in her saliva. In each situation, the body is able to recognize when the capacity to absorb free estrogens is reached. Beyond that point, excess estrogens become bound to other components in the body fluids, thus preventing these excess estrogens from acting as hormones.
The disclosed invention evaluates how a body fluid responds to changes in its capacity to hold or absorb free estrogens; alternatively the invention is useful in evaluating changes in estrogen solubility levels in the body fluid. The invention has many useful applications, and also clinical value as a tool for identifying physiological conditions affected by changes in free estrogen levels. This is especially true in females. It can be used to evaluate how a body fluid responds to changes in the capacity of the body fluid to absorb free estrogens, such as is observed in serum and saliva estrogen levels prior to parturition. It can also be used to evaluate how the body is absorbing estrogens given for therapy, such as in the prevention of osteoporosis or other conditions that benefit from added estrogen. It can evaluate imbalances in certain components sensitive to changes in free estrogen levels, such as observed in endometriosis, and it can track changes in free estrogen levels in the normal development of an individual, such as in the last stages of fetal development, the onset of puberty, and menopause.
It is accordingly an object of the present invention to provide a method and apparatus to easily and rapidly assess for changes in physiological conditions that are estrogen dependent by exposing body fluids, such as saliva, serum, or interstitial fluid, to anthocyanin pigments and to thereafter observe for color responses achieved by the pigments which reflect changes in the response of the body fluid to its free estrogen absorbing capacity of the fluid in order to monitor for estrogen dependent physiological conditions.